I’m a 70-year-old wife stuck with solo sex

I am a 70-year-old woman married to an 82-year-old man. Because of age and health problems, he cannot have intercourse, and shows no interest in any other forms of intimacy. I frequently have solo sex and he is aware of that. The problem is I feel so guilty and miss intimacy with a partner. Any suggestions? Sex outside of the marriage is not an option for me.